Forced Evolution
by Daemonmonkey
Summary: Izuku has a dangerous quirk, one that can rewrite the blueprint of everything alive. He still want's to be a hero though, and he has the best support he could get, in the form of his uncle and little sister. Bioshock elements. Izuku produces ADAM. Rated M for safety.
1. Nucleotides

I will say this here and now; this is _not_ going to be my main story until Powers you Earn is caught up with the manga. My updates on this will be sporadic, and random, so do not expect anything resembling a schedule. With that said, if Powers you Earn does catch up to the MHA storyline, then I will put that story on hiatus and work on this, or even another story. On to the story!

* * *

Izuku was in the doctor's office, Izuku was bouncing in his mother's lap with his All Might action figure in his hand. The doctor was checking over the notes before looking up.

"Well, Izuku does indeed have a quirk, though it's one of the more peculiar ones we have recorded." he confirmed before handing Inko a folder. Opening it, she found some odd pictures that showed a red liquid with glowing particles in a vial. "His body produces a bioluminescent substance in his body, mostly found in his blood, that had been able to modify genetic material."

"That sounds so cool! What's that mean?" Izuku asked, making both adults chuckle at his antics. The doctor did use big words, so he decided to clarify.

"All living things, from people to plants have what's known as DNA. It controls a lot of things about a person, from their max height, their hair and skin color, and of course, the quirk they possess. Are you with me so far kiddo?" he asked, to which Izuku nodded.

"DNA tells the body what to look like and what to do." The child responded. The quirk doctor smiled and nodded.

"That's very good! Now what your quirk does is make a special substance that glows, called bioluminescence, that can change DNA of any living thing if given a command to do so." Izuku's eyes were now wide in joy.

"So I can give myself multiple quirks!?" he asked excitedly.

"In theory, yes. Though if you want to use your quirk, I highly recommend you do so in the hospital under medical supervision and work small; you are messing with what makes you, _you_ after all." The doctor warned. Inko thanked the good doctor before walking out of the hospital with her son.

"Hey, mom?" Izuku inquired. Inko looked down. "The doctor said messing with DNA is dangerous. Can I learn about it first?" Izuku's mother smiled and gave a kind nod. She was going to have him learn the basics first anyway, and if he was comfortable afterward, then bring him to the hospital to experiment.

* * *

It's been three months since the doctor confirmed Izuku's quirk, and the child was ready to try out his quirk. He surprisingly, or not depending on the view, was talented in learning anything that related to biology. He still had trouble with many of the big words, but decided to give them nicknames instead and continued on.

"Alright little buddy, all of the equipment is set up. You're good to go!" the nurse, named Grace, called to him. Izuku, holding his mom's hand, nodded and focused on the light inside of himself. He rarely saw it, as he didn't like being hurt, but Izuku instinctively knew how to control the 'bio-glow' to change him how he wanted. He hated being one of the shortest kids in class, so he focused on making his build taller. Feeling pain, he didn't know whether he was doing anything wrong or not, so he looked at the nurse that he was with.

"I hurt. My joints hurt. This isn't fun." he told her, and Inko bent over to hug him.

"Can you tell me how much it hurts? We can stop at any time." the nurse informed the child. Izuku shook his head no.

"It's like I played all day and I wake up not wanting to move." he tried to articulate. Inko held him tight, and Izuku hugged her in return. He didn't know changing himself hurt like this. Katsuki's explosions didn't hurt him, right?

After a while, Izuku's pain went from being very sore to a dull ache, like he had just run fast and was out of breath. He told Grace how he felt.

"Well, that's good. You'll probably hurt for a couple days until your body heals. Come back then, or if you have any sudden pains that hurt more than they did right now." she rattled off before pulling a lollipop out for Izuku, who was more than happy for it. The little boy then hugged the nurse before returning to mom.

"Thank you for your time." Inko bowed.

"It was no trouble. Keep an eye on him, and make sure he -" the nurse said before being interrupted.

"I don't hurt anymore! It's all gone!" Izuku shouted, patting his elbows and knees. Grace, getting over the initial shock that days of soreness was reduced to not even _ten minutes_ , smiled.

"Well, if you're okay then I can supervise another change, but no more than for a few days; you need to get used to any change you make. If that is alright with you, Midoriya-san." Grace turned to Inko, who looked a little unsure.

"I trust Izuku, but I don't know what limits he has. Is it safe?" she asked. The nurse shrugged before answering.

"It's safer here than at home, that I can guarantee. Whether it's safe period, I don't know. Quirks like his are rare, and little is known about what limits he could have." she admitted. Inko looked at her son's hopeful eyes, and caved.

"At least if anything goes wrong, he'll have people to help." she assured herself, giving consent. Izuku grinned before focusing once again. The first change was aesthetic, but if he was going to be a hero, he needed to be strong like All Might. He focused on how his muscles were built, and made them denser, more compact. Soon, he felt his body feel like it was burning up.

"Un… can I get some water?" he asked, trying not to sound in pain. He was having second thoughts about how good of an idea this was, but he felt it was a bad idea to stop in the middle, so he endured. Grace quickly left and came back with more than one water bottle. Izuku took one with a raspy 'thank you' before downing half of it rather fast. His body soon felt the burning sensation lessen enough it was bearable.

"I don't wanna keep going." he mumbled as he leaned heavily on his mother. Inko assured him he didn't need to before bowing to Grace. Izuku was better after six minutes and thirty seconds, as Grace used a stopwatch this time. She told them she was updating Izuku's quirk registry, but they were only paying half an ear.

Right now, they just wanted to go home.

* * *

Izuku was having a bad day. It was a week since his first time testing his quirk at the hospital, and he had told everyone in class what his quirk was.

And Katsuki had to make fun of it.

"So you control what keeps us alive?" he accused, not understanding just what 'genetic material' was. "That seems more like a villain's quirk to me Deku. how can you save anyone with a quirk like that?" It was enough to make Izuku cry, and Katsuki made fun of that too.

He was playing in the park by himself to try and cheer up while his mother was off on a bench. Izuku was chasing a butterfly until he heard someone mumbling. Turning to the sound and following it, he came across a young blonde man with a scar running up his forehead sitting by the creek, talking about how 'am I me, no, I'm me, right?'. Izuku remembered the rule about stranger danger, but the man looked like he needed help.

"Um… are you okay?" he called from behind a tree. The blonde turned suddenly before he saw the green-haired child.

"H-hey k-kid. I'm al-no. I'm alright." he said brokenly. Izuku came from behind the tree and sat down, far enough away he could run if the man was dangerous.

"M-my name's Izuku. What's yours?" he asked politely. The blonde twitched and smiled, like he was in pain, but masking it.

"Bubaigawara Jin." he answered.

"You don't look alright, do you want me to get my mom for help?" Izuku asked quietly. Jin twitched.

"Yes! N-no! Can she? It doesn't matter." he answered, as if multiple people were talking from the same mouth. Izuku frowned at the confusing response. He decided to err on the side of caution.

"Don't go anywhere, I'll be right back!" the child promised before running off. Jin didn't move from his spot.

"Mom, mom! Someone by the creek doesn't look good, and he's not talking right. He may need help!" Izuku called to his mother, who reacted calmly and quickly.

"Alright, show me where. Was he hurt?" she asked while following her son into the brush.

"I don't know, but he kept talking about him being him, but not himself. It was confusing, but I don't know what to do to help him." Izuku responded. Soon Inko saw the man her son had talked about, and just hearing his mumbles, she could tell he wasn't in his right mind.

"Sir? My name's Midoriya Inko, my son asked me to see if you needed help." she spoke softly to Jin, not wanting the young man to panic.

"Help?" he almost whispered. "Yeah, I need-no I don't. Everything's fine-no, no, it's not." it hurt Inko to see anyone like this, let alone someone so young.

"Everyone needs help, Jin-san, or else they'd break. Let us be your hero." Izuku asked nicely, leaving Inko worried. Jin looked up from his mumbling and stared straight at Izuku.

"Heroes save the virtuous, not the broken like me." that… was the first thing he said without contradicting himself.

"Oh, honey." Inko cooed as she went up to hug him, her son following close behind. Jin flinched at the initial contact, but he thought, all of him thought, that it was better than being alone.

* * *

They were in the hospital, having Jin talk to a therapist. He had a duplicating quirk, and after cloning himself so many times, he couldn't tell if he was the real "him" or just the last clone standing from an all-out brawl. He left with a script, and a date to return on if to check if they were helping.

"Thank you both-I don't need-" he stopped himself before insulting them. "I'll try not to let your- it won't go to waste." though his speech broke, they knew the message was similar.

"It's more than alright dear. Do you have an address we can drive you to?" Inko asked. Jin shook his head.

"Couldn't- job didn't want- keep my job." he managed to get out. Inko took one look at him, sighed, and decided to go the extra mile.

"Would you like to stay with us then? At least until you get back on your feet." she offered.

"Huh?" was the blonde's intelligent response. "Why me? What did I do to be treated like I'm worth something?"

"You exist." Izuku said without hesitation. Jin looked at the child before smiling. He knelt down and hugged the first person who had just tried to help, and was changing his life.

"Thank you… thank you…" he kept repeating. The three left the hospital and Inko drove them home. In the passenger's seat, all the voices in Jin's head agreed on one thing.

 _These people are worth far more than me, so I'll help the best I can._

* * *

Izuku was turning twelve this week, and he couldn't be happier. His uncle Jin was living in a flat close by their house, visiting often. Eight years have passed since Izuku found the scarred blonde, and he now couldn't think of him anything other than as family. Jin had gotten better at his quirk, using it to make puppets (not copies, he's never giving them a will of their own again.) for Izuku to experiment his quirk with. When he got a result right, he'd change himself to get the new ability.

He did screw up though, but hopefully, that could be fixed. During a self-modification, someone interrupted his focus, and his body's chemistry shifted in the wrong place. His lower spine now hurt constantly from a malformed vertebrae, and until they could fix it, he wasn't supposed to tamper with himself.

The gene splicer was brought out of his musings by something crashing into him. Looking down, he saw a scared little girl, barely older than three. On instinct, Izuku picked her up and gave the little girl a warm hug.

"H-hey, are you okay?" he asked. She shook her head frantically and mumbled something Izuku could only just hear.

"I don't want to go back _there…_ " her voice was weak, and Izuku noticed her lack of weight. He took a glance down and saw her arms under her unkempt hair covered in bandages.

"Alright then, how about we go to my place, and we can call the police and sort this out. You don't have to go back." Izuku's voice was as soothing as he could make it, but seeing her grab him like he was a lifeline, tears fell from the genetic writer. He ran back home, forgetting all about school. He slowed down gradually until he briskly walked up to his front door and threw it open.

"Mom, call the police!" he yelled as soon as he closed the door. Inko came running down the stairs, ready to ask what happened, when she saw the tiny girl shivering in his arms, holding on like she was scared for her life.

"Alright then. I'll also call the school and tell them you're not coming today. Get her some food." Inko said with a fire in her eyes; no little girl should be that terrified. Izuku nodded and walked into the kitchen.

"Alright then, what do you want to eat?" he asked, but the little girl didn't respond. Taking a safe bet, he picked an apple and a small knife, careful she didn't see the sharp tool and panic. He cut the fruit up into little rabbits as his mom showed him, though they weren't as pretty as she made them. Putting the knife out of sight, he pulled the ash-haired girl from his chest. He was a lot taller than her, due to both his self-modifications and her tiny frame. She was reluctant to let go, so Izuku sat on the chair while putting her in his lap.

"I made you some apple bunnies to eat. Would you like some?" he gently prodded. The little girl nodded before taking one slowly. As she ate the first apple slice, her eyes widened and she quickly reached for another and ate it quicker. Izuku smiled as he took his time looking over his charge. Her eyes were red, and her hair was just shy of white, so he guessed she was albino. The odd thing was the yellow horn sticking up from the right corner of her forehead. She was skin and bone, and far too light for someone her age, meaning she was probably underfed.

"Un…" the pre-teen was brought out of his musing when she finished her plate.

"Would you like some more?" he asked politely. she nodded and he picked her up again. Questions could wait; right now, she needed a hero, and Izuku would be _damned_ if he wasn't going to be one for her.

* * *

Holy cow that was a lot of scenes I wrote. Anyway, a thought came into my head while watching someone go through Bioshock 2; what if ADAM was in the My Hero world? Then the idea of a Big Daddy Izuku caring for Eri, and I decided to say 'what the hell?' and write it. So yes, Izuku is technically a Little Sister (brother?), and will grow up to be a Big Sister (brother). Also, looking at how Kohei wrote Eri's quirk, I thought she'd be a good counter to Izuku, and vice versa; one can evolve, the other can reverse evolution. Jin I'm writing as in his early twenties, because the cloning problem he had sounds like a college fuck up to me. Eri is three, because story reasons, and the translation I read of MHA said quirks usually showed up _around_ age four, not at, so hers came in earlier. Anyway, there will be a few more Bioshock references, but not enough to count as a crossover. Thank you for reading, leave a comment, and till next time!


	2. Backwards and Forwards

Her name was Eri. It took a lot of coaxing, promises to not leave her, and hugs before she told them even that. Her statement to the police was vague, and she avoided giving names, but it was clear from her reactions and body that she was abused. She met Jin, and he doted on her like he would Izuku.  
Then they found out her quirk.

It was a couple of weeks since she was found, and they needed to get her a physical to see if there was anything in the database, as well as register any medical issues she may have. When Izuku was there she was well behaved, but it was clear the hospital scared her. Some tests she had no fuss with; checking her pulse and breathing, a blood pressure test, and seeing the scars under the bandages.

Yeah, _scars_. If they ever found out who did this, neither Jin nor Izuku were sure they could, or would, hold back.  
When they asked for a blood test though, Eri had a panic attack. Her breathing became ragged and she was shaking. Izuku held her to him tight. Then there was a crackling sound coming from the small girl's horn, and Izuku was crackling with energy.

' _She changes DNA as well? No, she's reversing the changes I made! Not even I can do that!_ ' he thought with excitement, until Eri didn't stop. Izuku, thinking fast, started to change his body right then, leaving his state more or less in equal flux. The change he picked to have was a marking on his wrists that looked like chains. It was a harmless change, and one he could overdo without negative consequence.  
"I… I don't know how to stop!" Eri panicked further, and the nurse ran off to get someone who could nullify her quirk; most hospitals had someone on call in case someone lost control like this.

"Hey, Eri-chan? Look at me." Izuku said softly, even though he was feeling rather uncomfortable. When the scared girl looked up to see his warm smile, her power started to get under control. "I'm fine, you're not hurting me. My quirk forcefully evolves my body, and you're just reversing some changes. It's not hurting me any. I'm _not_ going to let go." his voice kept lulling her into comfort. Soon her power cut off, and all Izuku had to show was exhaustion and a natural tattoo on both wrist below his palm.  
The nurse came rushing back in, only to find Eri passed out in her hero's lap.

"What happened?" she asked breathlessly.

"She panicked, and her quirk activated. It reverses genetic history, the opposite of what I do, so I just balanced the forces out." the green-haired preteen responded as he stroked her hair. The nurse nodded and wrote down what he said was her quirk; if it could do other things, then they'd find out later. Izuku carried Eri to Jin's apartment, where he was hanging out with today for experiments. The walk was peaceful, with little Eri cuddling into Izuku's chest with a calm expression. It was hard for her to smile, but everyone could tell that she was happy.

* * *

"Hey kiddo!" Jin greeted at the door. He was doing a lot better since he was taking his meds, though there were still spells. "Come in! I've got some snacks for Eri while we try and get that shock absorption quirk to work." he said, leading them in. Izuku noticed a change when he sat Eri down on the couch.

"Where are the ashtrays?" he asked. The scarred adult grinned as he rolled his sleeve up, showing a transparent patch.

"I've been trying to quit since Eri first came over; If I'm going to be with the two of you so often, I don't want you two picking up cancer from secondhand smoke. Next Tuesday I'm getting a steam cleaner and getting rid of the nicotine scent." he responded with pride.

"That's great news!" Izuku praised. He knew how the cigarettes calmed him, so quitting was going to be hard. Soon, they were running tests, Jin duplicating Izuku while leaving everything but his personality there. Izuku took a syringe set from his backpack before inserting a glowing vial into it. Injecting it into his double, Izuku willed the Bio-glow to shift the duplicate's anatomy. The skin shifted into a slightly darker tone until Izuku was sure it was complete. Pulling a sledgehammer from the closet, Jin handed it to Izuku. The scientist gripped it, and steadied himself before braining his mirror. The body dissolved as it took a killing blow.

"Damn, and I thought we had it this time too." Jin sighed.

"It's fine, round two?" Izuku responded with a sigh. The duplicator nodded before making another Izuku puppet. This time Izuku looked over it to see if his age had affected his uncle's copy. Any differences meant it was less durable. After going over some parts, he noticed something odd.

"Hey, Jin-san. There's no new mark." he said. The blonde looked over, and Izuku showed the melanin-made tattoo on his wrist side-by-side with the clone's bare one.

"That's new. When'd you get it?" the adult asked. If the kid wanted a tattoo, who was he to judge. Wasn't the worse he did at that age.

"Today. Eri's quirk went haywire. She reverses genetic history, and she accidentally used it on me. My spine doesn't hurt from the last change anymore, like it was never there." Izuku explained. "I needed to change myself to cancel her quirk, and a mark like this has little consequence if I went too far." Jin's eyes went big.  
"Kid, that's a scary quirk. She could _remove_ peoples quirks if she practiced." the adult said with awe.

"Yeah, I realized." Izuku said before thinking a little. "Wait, she can! That's _brilliant_!" he jumped up, startling Jin. "If she reversed my traits in order, and I know she did, I could work with her and finally work on gaining emitter quirks! She could learn how to control her quirk, and I can experiment on myself with fewer risks!" Izuku knew the dangers of making emitter quirks was higher just for the fact of backlash; someone who can control fire isn't necessarily fireproof after all. Before Izuku could continue his thoughts, a scream came from the other side of the door. Izuku bolted to the source instantly, and came into the room to see Eri crying on the couch.

"Eri-chan!" Izuku and Jin shouted in unison. The preteen grabbed her before making shushing noises.

"It's alright, Eri-chan." he comforted. "No one's going to hurt you. No one's taking you from me." he tried to console, but Eri just hid in his chest.

"You're alive. I thought… I thought my curse…" she didn't say any more, but Izuku now knew what was upsetting her. She thought she killed him with her quirk, even calling it a curse.

"Yeah, I'm alive, and I'm even better than before because of your quirk." he rubbed her back. Eri looked up in confusion. "Remember when I said my quirk forcefully evolves me?" she nodded.

"The thing is, I can only go forward, not backward. I hurt myself with my quirk before, and yours reversed the process. It's not a curse, just a gift you just don't know how to control." the little girl's tears were slowing down, and Izuku went the extra mile.

"Can I ask you to use it on me in the future?" he rubbed the tears from her eyes. Her puzzled face would have been cute if not for the traces of fear in them. "I want to be a super cool hero, but I need strength to do that. If I try and change myself and it hurts me, I can't take it back; _you can_." Eri teared up again, but Izuku could tell she wasn't sad or scared.

"Let me help you be the best hero, Onii-chan!" Eri declared, giving Izuku the strongest hug she could. Smiling at the term, Izuku decided he was fine being a big brother.

"Thank you, Imouto."

* * *

After several tests done on Izuku, it was confirmed; the genetic screw-up was no longer in his DNA. He also lost a bone density modification, but that was easily fixed. It took some convincing his mom, and the doctors, but If Eri could help him with his self-modifications, then he could try for grander things.  
Geneticists were already having a lot of data sold by Izuku on what the genome could do, but with the child's help, they could explore genetic flaws and see about treating genetic diseases. Back in the hospital, Izuku saw a black-haired man with Grace; likely someone who could cancel Eri's quirk.

"Alright, let's try a simple energy quirk first. Eri, what's your pick?" Izuku asked his sister, who was sitting on his lap. She put her finger to her chin in thought before answering.

"Fire…" was the result. Izuku remembered how much candles helped calm Eri, and guessed it made sense. Focusing on his inner light, he forced the change. He decided to start small, and go for the equivalent of a lighter. His hands grew hot, and he noticed his fingers glowing red. After a few moments, his hands burst into flames. Eri jumped at the burst of heat, but until her brother told her, she'd trust him. Though try one turned into a bust.

"Alright Eri, this didn't work right. Please help me." he asked, and she obliged. The crackle of her horn filled the room as Izuku's hands returned. She tried to reign her quirk in, but it was slow going.

"Come on, come on…" she tried, and all of the sudden her quirk disappeared.

"So that's why I'm here…" the raven-haired man said blandly. Izuku, putting the pieces together in his head, realized who it was that was with them.

"You're Eraserhead! Your quirk lets you negate transformation and emitter type quirks!" the hero-nerd exclaimed. The now dubbed hero smirked.  
"Good job kid. Not many adults can guess who I am without my goggles, f at all." Eraserhead praised. "But if you want to continue this, I recommend just getting to it."

"R-right." Izuku acknowledged. He tried another time, and again he screwed up, but now he at least had a starting base for what he needed to accomplish. Eri was more able to control her power but still needed Eraserhead to stop it completely.

The third attempt was a success.

"Yes!" Izuku fist pumped when his change didn't explode. His hands were still glowing as if a light was behind them, and his palm and wrist looked charred, but he didn't feel pain. Flicking his thumb out, a candle-sized flame lit into existence.

"Good work. You are now a pyrokinetic." Eraserhead congratulated. "Though you'll need to stop for today it seems."

"Yeah. but it's good progress. Thanks, Imouto." Izuku hugged his little sister, who looked exhausted. She snuggled farther into her brother's embrace. Looking back to the pro-hero, Izuku bowed.

"Thank you for this. You have no idea how much this means to her."

"Exhaustion from not being able to stop your quirk is illogical. It's-" he was cut off.

"No, not that. When she first used her quirk on me and passed out, she woke up thinking she killed me. Even if she decides to never use her quirk, she should never be afraid of it. I just hope I'm doing the right thing for her." Eraserhead was shocked. He understood that the boy found her when she had run from home, but to hear how bad she was, is, hurt him.

"I'm free Saturdays. If you're going to do this, might as well make sure we're doing this logically." the tired hero said.

* * *

Well, that was fun. Izuku has a little sister and Eri now has a big brother, and hope for happiness. Also, Jin is doing much better. He may not like the therapy visits, but he knows they are helping. Inko Didn't get much screen time this chapter, and maybe not next chapter either. But thank you all for reading. Leave a comment and Till next time!


	3. Bound by Chains

"Hey, Jin-san. I've been thinking about the markings lately." Izuku said as everyone was watching the news. It was a lazy day, and they were relaxing. Inko was having tea at the table while the boys were on the couch. Eri was sleeping in her brother's lap, warm from the sweater she took from mom's closet.

"Yeah? And what was the conclusion?" he asked.

"Well, since you have so much trouble making them on your duplicates, why don't I give some to you?" Izuku answered. "That way, if you need to make clones of yourself again, you'll be the only one who has them. You'll know you're the original."

"Wait, _what_!" the blonde turned his head quickly, but made sure to stay quiet for Eri. She seemed to always be tired.

"You'll be able to know who's the real you." Izuku repeated. Inko, hearing the conversation was shocked in how Izuku thought of a solution to Jin's long-standing problem; Identity crisis.

"But what if I manage to?" He asked nervously. The preteen was giving a shot of hope, but hope was scary.

"Then I'll try something else. But it's a shot." and that it was. Jin looked at the natural tattoos on Izuku's wrists and thought about it. After the news went to the drop in hero patrols in Hosu, he gave his answer.

"What do I have to lose? Even if it doesn't work, I'll get some pretty cool tats."

* * *

Everything was set up in the hospital. It had taken several hours of convincing and a crap-load of paperwork, but they got the okay to do it. The doctor had taken Izuku's blood, taken the Bio-Glow out of it, and sent the blood back into the preteen. Jin was in a reclining chair as everyone moved around him. The nurse took the syringe of glowing substance and put the needle in the blond's arm. After the contents were released, they backed off and let Izuku manipulate the Bio-Glow.

It was different, molding someone else's genetic structure, compared to messing with his own. Doing it to himself was easy; have a basic idea of what he wanted, focus on the light, and _push_ for the result. Now he had to work with finding the light in his uncle-figure, take count of how much material he needed, and then carefully guide the substance to work on a single part of his genetic code. As he was changing Jin, he realized they overshot on how much Bio-Glow was needed. It was expected, as he wasn't able to guess how much he used when Eri was trying to de-evolve him. After a while, Jin started rubbing his wrists in discomfort.

"Done, with plenty of room to spare." Izuku announced. Jin looked at his hands and saw the chain-like markings coming into sight just where Izuku's were. "There was enough Bio-Glow left to repair anything that went wrong."

"Glad for it too; this feels weird as hell." the scarred blonde said. The Bio-glow had a few unique properties that Izuku found rather nice add-ons to its main purpose. First was that if it wasn't rewriting DNA, it would help accelerate the healing process of anyone it was in, which made Izuku a regenerator. The second was that it was a sterilizing agent outside of Izuku, which meant that, in theory, Izuku could pull from himself, and immediately use it on anyone without harming them. The third was that it had a lifespan, preventing it from being cultivated outside of Izuku or, and it was not known why, sea slugs. This was why Izuku had a tank of felimare in his room, just in case.

He also liked how pretty they were.

* * *

It had been an entire year since Eri was found by Izuku, so they decided to celebrate it as her birthday. It was going to be small, as Jin was the only one who was coming over beside the Midoriya's. Inko made an apple cake, and Izuku set up some streamers. There were also presents that everyone got for her.

When she came down the stairs, they greeted her with a warm smile and pancakes for breakfast. No one wanted to try a surprise because Eri could still be a little jumpy at times. She gave a small smile as they helped her up into the chair. She swayed a bit before eating her food. Izuku noticed her tired look had gotten worse before, but now he was getting worried.

"Eri, are you feeling alright?" he asked carefully. His little sister looked at him before shaking her head reluctantly. Izuku checked her pulse and temperature. "Guys, she needs a hospital." he warned. Inko looked at her daughter as well, and turned to her son.

"Go, we'll catch up." she says. Izuku nodded, grabbed Eri, and started running. His long, powerful leg muscles were making the trip fast and only sped up from there when Eri passed out in his arms. The pneumatic doors to the hospital almost didn't have enough time to open as Izuku charged the front desk.

"My sister's sick." he said breathlessly, and the receptionist quickly called a team of nurses down. Izuku was handed a small stack of papers on a clipboard, and he easily filled out what he knew, left the things his mom or Jin would know blank, and the boxes no one knew as n/a. As the staff arrived, Eri was put on the stretcher, shivering. The gene splicer sat on a chair in the lobby, silently crying in worry. Grace saw him as she was passing by, and sat next to him.

"Hey Izuku, what brings you?" she asked. Izuku and his mother were emotional, and the nurse knew tears could mean anything from being sad to happy or even angry. This didn't seem to be the case today.

"Eri-chan wasn't feeling good, and her heart rate was so high, and she was cold. She passed out as I ran here." Grace hugged Izuku in comfort. The young teen returned it. Inko and Jin soon arrived, and filled the blank spaces in the paperwork. Eri's family stayed in the lobby, trying to comfort one another while still scared for her. After an hour had passed, they were allowed to see her.

Her room was white like every other one in the hospital. She was sitting up in the bed, dressed in a hospital gown. Her skin was a healthier color than before, and she was attentive instead of her usual drowsy. Izuku walked in before immediately hugging his sister.

"I'm so sorry I didn't notice before…" he said through tears. Jin stood by the door, making sure she wasn't overwhelmed. Inko talked to the doctor about what happened, and they found out she had a genetic fault that made it hard for her bone marrow to make red blood cells. She passed out from anemia.

Thankfully her big brother was both able and _more than_ willing to fix the issue at the source.

* * *

"Alright, I've figured out where the main issue is. Eri, is there anything else you want me to add onto this?" Izuku said. It was a week since Eri was first put in the hospital. Izuku and Inko stayed overnight almost every day while Izuku poured over his books to see what he could do. Eri responded by showing her pale wrists.

"I want Onii-chan's tattoo." she said quietly. The now-teenager found the response odd.

"Why?" he asked.

"Because it shows we're family like Jin-Oji is." she replied, and Izuku hugged her.

"We're family no matter what; your genes mean nothing, or did you forget about me?" he joked. Eri returned the hug tenderly, and Izuku had an idea. "What if I change your hair? Mom and I have green pigment in our hair, so I can easily give it to you." Eri looked up.

"Can you?" she asked, and her brother nodded. She agreed to the change, bit still wanted the melanin tattoo. Later on, Inko heard of her daughter's request and thought it was the cutest thing. She agreed to the changes and filled out the paperwork; changing the DNA of another person went through a lot of legal hassles under the title of gene therapy; it technically _was_ , but it was much safer than using machines that couldn't change mid-procedure.

After everything was said and done, Izuku started the treatment. He started in her bones, fixing the defect and making sure he didn't go too far and making another issue. Then he turned attention to her follicles, changing parts of the few pigments she had from melanin to porphyrins like his and his mother's hair. She would have a lighter hair tone, but it would still be green when it grew out. Last was the melanin chains, which were easy, as he'd done it before. Any leftover bio-glow would heal any lingering damage and accelerate her body's production of blood to get a more healthy pressure in her veins.

"Done." Izuku announced, and Eri was waiting for the discomfort to go away in her mother's arms. She was soon released from the hospital and driven home. Looking at the calendar, she remembered what day it was and started crying.

"Nonono, what's wrong Imouto, do you hurt, did I-" Izuku started fussing when Eri cut him off.

"It's Onii-chan's birthday, and I didn't get you a present!" she shouted in tears. Izuku looked at the wall and saw, sure enough, that it was July 15. Izuku's parties were small like Eri's was going to be, but he didn't mind missing out this year.

"But you did." he answered with a smile. Eri looked up in confusion as her brother wiped her tears away. "You did, and it the best one I could ever hope for; you're home and healthy, and that's all I need."

Eri continued crying, but Izuku could tell they were happy tears now. Inko soon came in to join the hug, and soon the three Midoriya's were crying together.

Whatever happened next, they'd still be family, and nothing could change that, not even blood.

* * *

"The shock absorption is still being difficult, and I don't know why. Is it because of the bone density modifications, but then how could someone with a shock absorbing quirk function without looking like rubber? There has to be a skeleton to hold them in shape. Is it a matter of tensile strength, or should I just forgo the idea and try for a transformation hardening-type quirk? How would I balance the pressure strength though without shattering my skin then? If I could only find someone with a similar quirk, I'd get a baseline. Well, the elemental quirks are coming along anyway, though I've yet to figure out how to use them simultaneously. Maybe by-" Izuku's head was tapped on by the teacher to get him to stop mumbling.

"Jeez Midoriya, at least speak loud enough for anyone to hear you." he joked as he continued his talk about everyone's career choices. There were some murmurs when Katsuki gloated about going for UA, thinking he'd be good for it.

"Oh yeah, Midoriya's going to try as well!" someone noted, and all attention turned to the tallest kid in the room.

"Yeah? I'm going to be a hero anyways; might as well aim for the best instead of what's a safe bet." he said without fear. Few knew how Izuku's quirk worked, as it changed every week, but most everyone thought he'd get in with brute strength and intellect alone if he needed.

"The fuck Deku! You trying to steal my spotlight!?" Katsuki shouted, explosions igniting in his hand. The gene splicer looked at him without blinking and responded.

"I'm not trying anything to Bakugo; whether you were going to try or not means _nothing_ to my choice." Izuku wasn't condescending, but everyone saw the casual way he deflected the blonde's aggravation.

"And how are you even going to do it? The entrance exam wouldn't let you change a proctor without arresting you!" the explosive teen said, never bothering to understand Izuku's quirk.

"I could do it in two ways. The first is showing that, unlike you, I can _heal people_ ; Recovery Girl was a hero despite never fighting a villain, and consistent gene therapy is a very hard thing without a quirk like mine. Secondly, I don't need to modify a proctor; I'll change _myself_ , just like I have since I was four." Izuku explained without batting an eye. Everyone in the room stood as the two strongest teenagers in the room stared down each other; one with unbridled rage, and the other with an air of poise. After a moment, Katsuki tch'ed and sat back down. He'd see who was better in the exam ten months from now.

* * *

That's enough for this chapter. Next up is the entrance exam! I'm also going to put this here for not needing to write a whole scene; Inko also has the natural chain tattoos a couple months after Eri; it became a family thing. Got the Idea from persona 5 and Iwai. leave a comment, and I will see you all later. Till next time!


	4. Exam

Izuku was visiting his uncle again, but the person answering the door wasn't his uncle. It was a blonde girl around his age with messy buns and an uncanny smile.

"Hi! My name's Toga!" she answered cheerfully, but the gene splicer knew that it was fake from the exaggerated movement.

"I'm Midoriya Izuku, it's a pleasure." he said with a smile of his own, noticing her mild shock. It either meant she was used to loud people, or people not liking her. "Is Jin home?"

"That Izuku? Come on in kid!" the scarred blond shouted from the living room. Toga let Izuku in and closed the door behind. The greenette noticed the stiff movement, but didn't comment. Walking into the main room, Izuku grinned at the lack of a nicotine patch on Jin's arm; he had kicked the addiction.

"Yo kid, seem's you met Himiko. She's staying with me from now on." he explained, and the taller teenager nodded in understanding; if she wanted to share, then she would. He wouldn't push. "Anyway, you up for a trip? she's got community service at Dagoba beach, and it's 'bout time to leave."

"Sure, you want a hand?" Izuku asked Toga, who looked at him like he had grown two heads. "What? They've dumped _fridges_ and _stoves_ over there. Unless you're stronger than you look, hauling those things around would be next to impossible."

"S-sure! Thanks, Izu-kun!" the blonde girl smiled more sincerely this time, but it wasn't fully natural. Izuku still blushed at the affectionate term. "Any help would be a huge help."

"I'm not letting him do all the work for you. You know that right?" Jin chimed in and Toga's shoulders slumped, making Izuku laugh. As the residents left to get their things, Izuku started writing notes in his "quirk analysis journal: 13". When the blondes came back, Jin in a black t-shirt and jeans and Toga with thick pants and a shirt that said 'knife to meet you' in hearts, Izuku finished his paragraph and closed the notebook. Toga looked over to read the title.

"'Quirk analysis'?" she questioned as they left for the door.

"Yeah." Izuku confirmed. "My quirk can change genetic structures, so I've managed to give myself multiple quirks. so what's yours?" he asked. The shorter teen turned anxious for a moment before covering it up.

"Aw, don't expect a girl to give away all her secrets! We just met!" she cheered.

"He ain't gonna care what it is, Himiko." Jin said over his shoulder. "Hell, he'd let you _use_ it on him if you ask." there was a moment of silence before Toga responded.

"I can transform into people I drink blood from." her tone was much softer this time, and Izuku could see the embarrassment. He suspected that she was told it was a villains quirk like he was. He just had support.

"That's a very useful quirk." he started, before his nerd side started taking over. "You could be a hell of a hero with that. Think of how many deep-cover missions you could do without even showing your face! Blood donations could be used as a base, as there are procedures to cultivate blood in bags, and that means you'd have a large number of appearances to work with! What's the duration, does it have a limiting factor, can you transform from one to another without showing your real face underneath? Do you "store" the person's appearance indefinitely, or is there a timeframe from ingestion to transformation?" Toga was taken by surprise while Izuku pulled his notebook out and rattled off question after question. Looking at Jin, he only shrugged at her.

"Told ya. The kid doesn't care about if it's a villain's quirk or not, only about the quirk and the person using it." he said without even glancing at his nephew. "His little sister would have killed him if not for his own quirk, but he still asks for her help." this made Toga smile, truly smile, at the chance to not be labeled like she had for so long. She turned to Izuku.

"How long I can transform is based on how much I drink. Drinking a cup of blood lets me keep the transformation for roughly a day. Yes, I can switch between people, and the timeframe is about six months." she answered in order. Izuku scribbled away in his notebook as they kept walking. Soon they arrived at the beach, but the teenagers didn't stop talking. Izuku lit a pile of wood on fire while they moved the metal debris to the pre-designated dumpster. If Toga didn't want to answer a question, Izuku didn't pry and moved onto another one. Toga asked Izuku questions herself, such as dreams and drives and even the specifics of his own quirk, to which he responded animatedly. After a while, the sun went down and they had to head home, but not before switching numbers and Izuku letting Toga take some of his blood with the promise not to do anything embarrassing wearing his looks. When she bit down and drank, Izuku didn't make a complaint. Looking at the wound she made after finishing, she noticed something.

"It glows!" she squealed like it was an awesome trick.

"Why do you think I called it _Bio-Glow_?" Izuku said with a laugh, feeling the wound heal. "See you later, Toga-chan."

"Oh, is it 'chan' now? Are you trying to flirt with me?" the blood-drinker smiled, and laughed at Izuku's blush. "Bye, Izu-kun!"

As the Toga left with Jin and Izuku walked home, they had similar thoughts.

' _It's nice talking with someone your own age.'_

* * *

It had been months since Izuku and Toga first met, and the beach had been cleaned after the third month. It would have been done sooner if anyone else had given a hand, but there was only so much two people could do in a day.

After her probation (which Izuku learned was because of assault) was finished, the two spent a lot of time talking and exploring each other's quirks. There were even times when the teens went to the mall and restaurants.

But now was the time to focus, as Izuku stood in front of UA, ready to take the entrance exam. He stepped through the gates he'd been aiming for since he could remember. Finding his number and sitting in his seat for the written exam, Izuku spent time thinking about the people in his life who had supported him. His mother had never left, even when she had seen him mutilate himself with both his quirk and mundane tools to test his limits. Jin was that uncle who would always lend an ear and give advice, even getting over his own fear of using his quirk to make sure his dear nephew was as safe as he could be. Toga was the crazy neighbor that never let you sit and mope, dragging him out of his darker thoughts while showing him what it was like to be _normal_.

And then there was Eri. His adorable little sister he would change the world for just to see her smile, who wanted nothing more than family and love. He still saw her marveling at the green tint to her hair and the chains at her wrist, that in her eyes, made her family all the closer.

The proctor came in and set the papers face-down in front of every teenager there before giving the signal, and Izuku started reading everything in the twelve-page test. He first answered all of the science questions before moving onto math, then reading and history. Izuku noticed the last questions were about morality, and he figured it was an important subject for people wanting to save lives for a living. He decided to answer the questions as if he was really there instead of what they wanted to hear. A lot of the questions were one and the same, but there were a few that he could tell probably weren't what they were looking for; he was a human, not a machine with programmed responses.

Izuku finished his test before the timer, so submitted it and left the room to not disturb the other participants. As he found himself in the waiting room with an emblem showing the letter C, there was another person who had already finished their written exam. He was almost as tall as Izuku, though shorter by a few centimeters, and had square glasses with a neat, dark blue hair.

"Seem's I'm not the only one who finished early. Midoriya Izuku." the gene splicer greeted with a bow. The other teen stood up to bow as well.

"Iida Tenya, a pleasure." he greeted almost robotically. Izuku sat next to him and saw his calves' exhaust pipes, and had to ask.

"I'm sorry if I sound rude, but may I ask what your quirk is? Recording them is a hobby of mine, and I can't help but wonder what those pipes are made of." he questioned. Tenya looked at him suspiciously, making Izuku sigh before pulling his notebook out and showing it. Looking at it and the latest page, the high-strung teen nodded.

"I do apologize, but I was worried you were trying to get an edge." Tenya said before answering. "My quirk is 'engine', and it boosts my relative speed through accelerating muscle contraction in my calves and thighs as well as granting thrust. They are made of Keratin with a high iron content to make them heat resistant. If they are damaged, they will regrow like nails."

"So it acts like a one-chamber piston and exhaust jet? That would certainly grant quite a bit of torque and acceleration. What's the highest speed you've gone?" he asked, and Tenya was impressed at the accurate description to his quirk.

"80 Kilometers per hour, though I was constrained by the track field's turns." he said, and Izuku's eyes went up.

"I'm impressed. Without a quirk, the physical limit of human speed is only 64 Kilometers per hour. That means your legs are that much more capable of turning torque into acceleration. Does it have any special requirements to use it?" the quirk analyzer inquired. After a few more questions, Izuku put the notebook away.

"Sorry if I was intrusive. It's just that I don't think I'll be able to focus on many quirks today, so I'm making up for the fact with more in-depth notes instead." he apologized.

"Not at all!" Tanya assured. "It's a good trait for a hero to have. Though to return the favor, how about you tell me yours?" Izuku nodded.

"Alright. Mine's called 'forced evolution', and it does exactly that. My body produces a bioluminescent material," he said while reaching into a pouch at his side and pulling a medical vial out to show it. The teen in glasses looked at the glowing green liquid with a curious gaze. "This lets me change the genetic structure of organism's it's inside. I've modified myself with this over years to get a body more suited to being a hero, and even mimicked the abilities of quirks. Though without my little sister, I can't reverse any changes."

"Oh, you're a brother then?" The engine quirk user asked and Izuku put the Bio-Glow back in its pouch. Izuku smiled and pulled his phone out to show him Eri. She was trying to paint and had absently put her loaded brush to her cheek, leaving a trail of blue down to her chin. "That's adorable."

"Isn't she?" Izuku grinned. "She can rewind genetic history, so she helps with my modifications in case I… screw up." the taller teen looked a little green, and Tenya could guess why; messing with something as versatile as DNA could easily lead to nasty results fast.

"Does DNA modifying run in the family?" Tenya questioned. "It seems that you and your sister have the same aspect of doing so."

"Huh? Oh, Eri's adopted; her quirk has no relation to mine as far as we know." Izuku explained. Before they could get any further in the conversation, the test had ended. Everyone was told to go to the auditorium to learn about the practical test.

"Ah, guess we'll have to leave this until later." Izuku mourned. "Good luck, Iida-san."

"And to you, Midoriya-san." Tenya responded before they left.

* * *

Izuku was at the gate in block C of the mock city, waiting for the signal while everyone chatted. He saw Tenya was in the same block, and someone actually as tall as him, which was rare now he was taller than average by a large margin. He thought of all the emitter quirks he had, and decided that he was going to focus on Frostbite and Live Wire for the test.

"AAAAND START!" President Mic called, and Izuku ran through the open gate. The voice hero said a few other words, but he wasn't paying attention. The lanky teen jumped and climbed a tall structure while scouting where the mock villains are. Seeing some, he leaped off the building and crushed it under the force of his fall. He shocked a three-pointer and got a bright idea.

"These robots have a recognition software linked to an attack command. If I just switch the "ally" list with the "target" list, then…" he muttered while messing with the electronics. Soon the three-pointer recovered from the electric surge, and Izuku knew he did the rewiring right when it shot a one-pointer and destroyed it. He decided shocking and hacking them to get points would be a better way than just charging in alone.

"SIX MINUTES FOLKS!" he heard from the announcer, and Izuku charged to where the largest amount of noise was. Turning a corner to see a free for all, Izuku shocked a few before freezing the three-pointer closest to him before his allied one shot it, breaking the plate and letting Izuku rewire that one as well. The second attempt was much faster than the first, and soon, Izuku had two robots giving long-range support to his close-up fighting. Izuku was counting somewhere around forty to fifty points when the proctor called for the two-minute time.

Then the zero-pointer showed up.

"That's the gimmick!?" he shouted to no one. His two allied robots were unloading ammo at it, but it was only denting the armor of the skyscraper-sized robot. He remained in the area while everyone else was running, helping the tripped to their feel and shouting others out of their fear.

"Owww…" Izuku heard a voice and saw a girl with brown hair underneath rubble and in the path of the zero-pointer. Izuku couldn't tell if it could even notice her. He then decided on a plan, and _acted_.

It was stupid. It was reckless. It was what heroes were _supposed_ to do.

The girl looked over and saw a tall, lanky boy running towards her and the massive robot behind her. She didn't know what his quirk was, nor was she sure they even met, but his eyes didn't show any fear as he charged her like nothing else mattered. Izuku stopped right in front of her and proceeded to lift the massive rock off of her like it was made of cardboard. Looking at the zero-pointer, he threw the artificial boulder at the massive enemy.

The impact staggered it, and Izuku took the opportunity to pick the injured girl up and get away. He jumped up a building off to the side, and realized everyone was grouping together, which would draw it to them. Izuku's hands glowed blue with lightning as he decided that it needed to be destroyed before it hurt someone. Taking a breath and anticipating the pain, the gene splicer lit his hands up and shot the robot with everything he had. His hands hurt, and he could smell burnt flesh, but even then he didn't stop until he saw a circuit blow near the zero-pointer's faceplate, signaling it's blind state.

"AND TIME!" everyone heard from President Mic. Izuku knew he didn't get the top score, but he was satisfied that he was in the higher numbers. Looking at the girl's ankle, he spoke up.

"The medics are down there; you want me to carry you?" the lanky teen asked, making her snap out of her stupor.

"Please?" she almost phrased it like a question. Izuku picked her up bridal-style before grinning.

"I almost forgot to Introduce myself; Midoriya Izuku." he said with a smile.

"Ochaco Uraraka." the girl greeted with cheer. Izuku nodded before climbing down smoothly to meet the nurse. Getting a good look, he recognized her.

"Recovery Girl! My friend needs a little help!" he called over. The elderly hero was surprised to hear her old handle from a young voice. Looking over, the healer saw a rather tall young man carrying a girl over a foot shorter than himself. The young man stopped in front of her before letting his carrier down gently.

"Thank you, dear. Would you like some gummy bears while I tend to her?" she asked politely, and the green-haired teen nodded as he sat down. Recovery Girl noticed the burns on his hands, but as he didn't act as if it hurt, she let it be for now. A quick kiss, and the young lady's ankle and scrapes were healed. She then looked at his hands. Noticing it, he shook his head.

"It'll heal before I get home without help. Just used Live Wire too much and hurt myself." he said without concern. Recovery Girl decided if he wasn't fussing over it, she shouldn't either.

"Why don't you go home dear. I'll make sure your friends alright." she told him, and the gene splicer nodded in understanding.

"I'll see you another time, Uraraka-san." he said to the brunette with a bow.

"Sure! Thanks for the save Midoriya-kun!" she cheered. Izuku smiled before walking to the front gate. Tenya stopped him to ask a question.

"Why did you destroy the Gimmick when you could have run?" he asked. The taller teen looked at him quizzically for a moment.

"Because everyone was crowding in panic; if I didn't stop it, then it'd just attack someone else. I didn't want anyone to get hurt." he answered with a straight face, hands still smelling like a bad roast. Tenya then knew that Izuku wasn't even considering the test when he destroyed the zero-pointer. He was just acting in the moment like it was a real scenario.

"Thank you then, for looking out for us." Tenya bowed, thinking something else.

' _This is a hero.'_

Holy hell, 3k words went into this! That's the entrance exam dealt with, and there are a couple changes I'm making because things happened differently. As for Toga, Jin was able to help her because the Midoriya's helped him. She still needs therapy, and she's on medication as well, but she hasn't killed anyone yet. But if you liked it so far, leave a comment! Till next time!


	5. results

"He rewired the villains." Shouta noted with incredulousness. "He short-circuited a three-pointer, and rewired it to fight for him before doing it again with another. Has anyone ever tried that before?"

"Power Loader did back when he was a student." Nezu stated, impressed at Izuku's ingenuity himself. There was more than one way to defeat a villain, and not all were through brute force. "Midoriya also showed great bravery and fast thinking when I released the Gimmick. I say he should have points from both his actions, as well as the actions of the robots he hacked."

"Wait, what about his self-harm?" Sekijiro asked. "I don't know about you, but I wouldn't trust anyone with my life if they would hurt themselves that badly."

"Midoriya stated his quirk would heal him quickly, and he was still able to act when he was hurt like that. I say give the kid some slack." Nemuri said.

"I agree, and he made sure both he and his charge were in the clear before taking the risk." Ken added.

"I vote for granting Midoriya Izuku 60 rescue points based on intent, skill, planning, and personal safety. All Agree say I" Nezu said there was a majority vote, and it was decided. Izuku gained 39 villain points and 60 rescue points, bringing it to a total of 99 points, breaking the previous records by a good margin.

* * *

A week had passed since Izuku's exam, and Eri started primary school. Inko had packed her bag and Izuku walked her there for the first few times until mom could do it. After some time, his letter from UA came in. He called Jin and Toga, wanting the whole family to hear the results at once. Once Eri came home from school and the extended family came over, he ripped the letter open. Inside was a metal disc with a button. Izuku set the machine on the table and pushed the button. All Might then appeared as a hologram.

"HERE I AM AS A PROJECTION!" the blonde hero bellowed loudly, making Eri flinch. Izuku held her hand in comfort while glaring at the projection. "YOU MAY BE ASKING WHAT I AM DOING IN SOMETHING SENT BY UA! WELL, THAT IS BECAUSE I WILL BE A TEACHER FROM NOW ON!"

"Is there a volume control on that?" Jin asked. Izuku looked at it but didn't see any dial.

"Wait, what's that? Hurry up? But I'm- wait, I'm doing this for _how many_?" All Might conversed to someone off screen before turning to the camera the next part was thankfully quieter. "Alright. Well young Midoriya, your written tests were exemplary, leaving you in the top five. Congratulations!"

"Wow. you're so smart Izu-kun!" Toga chimed in.

"As for your practical, your villain points were rather promising at 39 points. Not the highest, but beating up the villain isn't the only part of being a hero!" there was a clip in the video to the teen's rescue at the arena. Eri awed as her big brother fearlessly charged the massive robot and hurled a slab of rock at it. "For your valiant rescue in the face of imposing obstacles, the judges have decided to reward you with a massive 60 rescue points! This brings your total score up to 99 points, breaking the past record of 86!" There were tears flowing from Midoriya as he saw his placement in the test.

"Congratulations Midoriya; UA is now your hero academia." the hologram then cut off, leaving the room filled with silence. Eri was the first to break it.

"Onii-chan is the best hero!" the little girl shouted with a smile. This broke everyone from the silence as they praised the tall teen with pats and cheers. Deciding to go to a restaurant to celebrate, they didn't stop conversing. At one point Izuku would have been overwhelmed, but this loud, excitable family was his.

And he wouldn't have it any other way.

* * *

Izuku was walking into UA with a smile. He looked to where the board was, and saw a familiar face.

"Ochaco-san!" he called to the brunette. She looked over and easily picked the gene splicer from the crowd.

"Midoriya-kun!" she greeted in cheer. "I'm glad you got in! What class are you in?"

"That's what I'm trying to find out." he joked. Turning to the board, he saw his name and class number. It appeared he wasn't going to be in her class.

"1-A, darn. Seems you got 1-B." he complained. Ochaco sighed.

"I guess it's to be expected; I only got fifty-four points. Still, why don't we meet after school?" she compromised.

"Sounds good to me; how about switching numbers to stay in contact?" he asked. Uraraka nodded and they pulled their phones out. After messaging each other, they waved goodbye as they left for their respected classed. Walking through the school halls, he noticed the large corridors that made him feel smaller; he guessed there would be people that would require more space because of their quirks. He found his class and opened the door to shouting.

"The desk ain't got feelings to disrespect, four eyes!" Katsuki shouted. Izuku looked at the situation, and decided the only thing to do was inform his friend.

"It hasn't even been a _day…_ Iida-san, Bakugo won't back down; unless a teacher tells him, he's not going to budge." Izuku sighed.

"Midoriya! Good to see you. Are your hands well?" Tenya greeted with a bow. The gene-splicer blinked at the question and realized his friend was referring to the exam.

"I heal fast." he said, holding his hands up and letting the electricity dance under his skin. This brought the attention of a floating set of clothes.

"Ah, so it was you who took out the zero-pointer!" she said in excitement. Izuku nodded. "That was so cool! You just went ' _kerzap_!' and it started smoking like a fried computer!" Izuku's mind supplied him with an image of the hyperactive girl without needing to actually see her.

"If you're going to socialize, then leave. This is the hero course." a deadpan voice came from the door. Everyone turned to it to see Eraserhead in a bright yellow sleeping bag, though only Izuku knew who it was. The tired hero stood behind the desk and glanced over the class. "My name is Aizawa Shouta. You will refer to me as Aizawa-sensei. Now there's an introduction in the auditorium, but we're not going. Put on your gym clothes and let's go to the track field."

* * *

Izuku was put on the softball throw because he ranked first in the practical. His middle school record was a hundred and twenty meters, but now he was allowed to use any of his abilities. He added a blast of kinetics to his throw with Expansion's force. The machine displayed a result of three hundred and six, one hundred and eighty-six more than middle school.

"Before you know how to improve, you must know your limits. This is the basics." Aizawa said calmly. Soon everyone was getting excited to test their limits, until the teacher threatened expulsion for the one ranked last. The first test was the 50m dash, which Izuku did in in 3.08 seconds. Slower than Tenya, but still the second fastest. Then he went to the grip strength and was around three hundred kilos. Both Shoji and Ibara beat him, but he still outshone most individuals. His standing long jump wasn't as impressive as students with quirk better designed, but ten meters was still freaking long. The last test were side hops, and he didn't do as well as he hoped.

After everything was said and done, Izuku was was in third place, just above Bakugo.

"Alright, everyone change back into your uniforms. Oh yeah, the whole expulsion was a logical ruse." there were some people who were shocked, but Momo spoke up.

"Of course it was. He wouldn't expel us on the first day." Izuku looked at her.

"Bullshit. He's done it before." he said dryly. Everyone stared at the greenette. "He'll demand our best, but he's not afraid to tell anyone that they don't have what it takes; if anyone here half-assed it, he would have dropped us like a rock."

"And you know this how?" the creator asked with suspicion.

"Because I've met him before. He's the pro hero Eraserhead." Izuku explained. This made his classmates nod in understanding while others decided to up their game.

* * *

After class ended, Izuku walked out of the building with Tenya. The taller of the two heard his phone go off, and saw Uraraka messaged him where she was.

"Hey, Iida-san, would you like to join Ochaco and I for fun?" he asked. Tenya looked up and smiled.

"I'd like that." he said. The two walked to the gate and saw Uraraka with another girl, talking while they waited. Turning to see Izuku, the brunette waved.

"Hey, Midoriya-kun! This is Yui-chan; she wanted to hang out with us if that's okay." she said, and the black-haired girl nodded quietly.

"Of course!" Tenya exclaimed. "I was wishing to join as well!" Izuku grinned at his friend's excitability. As the three started walking to the train, the greenettes' phone rang. Looking at the caller ID, he answered fast.

"Hey mom, what's wrong?" he said, making his companions hold off on the conversation. "He _what_? That's ridiculous! No, don't worry. I'll get her. I'm hanging with friends, so I'll just pick her up before we hang out. Love you too mom. Bye."

"Did something come up?" Yui asked. Izuku nodded while taking a different turn. Everyone followed without thinking.

"Mom's boss was supposed to let her off by now, but he just told her to stay a couple more hours. I've got to pick up Eri from school now. We can still enjoy ourselves, just with her tagging along." He explained.

"You have a little sister? I wanna meet her!" Uraraka cheered. Turning a few corners and walking a fair distance, the high school students found themselves at a primary school. Izuku waited at the entrance until he saw his sister.

"Eri-chan!" he waved. Everyone saw the slight confusion until she found her brother, at which point her eyes lit up.

"Onii-chan!" she shouted in joy, charging him full sprint. Izuku bent down and caught her in a hug and squeezed. After a moment of them hugging, Eri noticed the other UA students and hid slightly behind her hero. Uraraka and Yui cooed at how cute she was while Tenya attempted to look less threatening.

"Eri-chan, these are friends from school. Uraraka and Yui are in the other hero-class while Tenya is a classmate." he soothed as he held his hand out for her. Eri took it before stepping out from behind him.

"H-hi…" she said softly.

"Hi!" Uraraka greeted while kneeling down to her eye level. Seeing that she was shy, the students backed off a touch while Izuku continued to talk.

"Something came up at mom's work, so you'll be with us for today; do you want to go anywhere?" he asked gently. The other teens wondered how someone who was usually not cold, but distantly friendly, turned into such a cuddly person at the drop of a hat.

"Um… the park." the horned girl said, more clearly than before. Izuku looked up to everyone else.

"Sound good?" he asked, and everyone agreed. The gene splicer then stood up while holding onto his little sister's hand. The nearest park was only a few blocks away, and soon Eri was on the playground while the high-schoolers were sitting under a tree. Tenya, remembering the conversation he had at the entrance exam, decided to break the silence.

"Back at the entrance exam, you said Eri was adopted?" he started with. Ochaco and Yui looked at Izuku in curiosity.

"Yeah, I met her only three years ago on my way to school." the greenette admitted. "She literally ran into me, scared out of her mind and crying. I decided to skip school and take her home. She… wasn't in a good state." he decided on. There was a heavy silence.

"The police databanks didn't have anything on her, not even a name. The hospital didn't have much luck either, as she refused any tests that involved sharp objects." hearing the description of how bad she was made Ochaco's heart clench. She was so sweet, who would even do that. "Then we found out her quirk 'rewind'; the ability to reverse biological and genetic history."

"You said something about that. What are the specifics?" Tenya questioned.

"It's linked to her horn, that we know. It also tires her out rather fast." Izuku answered. "The first time we saw her use it was during a panic attack. She's scared of needles, unless it's held by someone she trusts, and she freaked out. If my quirk wasn't the direct opposite of hers, I'd probably be dead." Yui shivered at the thought of not existing, but also at the fond tone the taller teen had the memory.

"That's scary. Did she learn how to control it?" Ochaco asked, and Izuku nodded.

"I wanted her to at least be comfortable with her quirk, so we went to the hospital to do just that; I'd modify myself with my quirk, and she'd reverse my state backwards if I screwed up. That's where I met Aizawa-sensei. If she couldn't turn her quirk off, he'd use his and erase it, effectively doing the same thing." that cleared a question up for Tenya, who was curious about where his classmate met the erasure hero before UA.

"Wait, ' _modify yourself'_? What is your quirk? You said it was the opposite of Eri's." Yui chimed in. Izuku then pulled a green vial out of the pouch on his pocket.

"I make what I call Bio-Glow, which alters genetic code. I've been modifying myself since I was four, but I had to be much slower in my experiments; I can't backtrack without Eri." as the day progressed, everyone decided to head home. When Izuku put Eri to bed that night, he wondered how tomorrow would go.

* * *

That's all! Man, why do these chapters keep dragging on? Anyways, yeah, Ochaco is in class 1-B instead, and Ibara took her place. Uraraka didn't save Izuku, so she got far fewer rescue points, leaving her to be placed in a different class. Anyways thank you for reading, so please leave a comment. Till next time!


	6. Battle

I LIVE! The story is not dead like many have assumed, simply not the priority. Still, as I haven't uploaded any for Powers you Earn in a while, I thought I'd pull another chapter out. Quick question though; regarding Izuku's costume, do you want it to stay as I wrote it, or change it in a later chapter to look more like the big sister from Bioshock 2 (I have an in-story reason why he would change it, so don't worry about that.)? Let me know in the reviews. Onto the story!

* * *

Izuku was waiting on class to start, as he heard everyone talking about All Might being the foundational hero teacher. The gene splicer was excited himself but was more focused on his conversation with Yuga.

"So the belt acts as a reflector to make your navel laser work less like a flashlight and more like a laser. That's rather neat." he said with a grin. "Even if you don't have the belt, you could use it like a beacon. Have you thought about learning Morse code?"

"Non, Midoriya-kun. I think that would be a merveilleux practice. It's a rather sore point that my superbe quirk needs assistance, but you have given me a new path to s'aventure. Is that enough for your carnet?" The sparkling teen questioned. Seeing the confusion, he clarified. "Carnet means notebook."

"Yeah, it's a really fascinating quirk." he praised. "I was curious about-"

He didn't continue though as All Might's voice rang from outside.

"HERE I AM, COMING THROUGH THE DOOR!" he shouted, and Izuku wasn't the only person who was excited. The class watched with rapt attention as the number one hero walked in the door.

"Foundational studies! For this class, we'll be building your hero foundation through various trials! Let's jump right in with this!" he said while holding a card that had the word 'Battle' on it. "This will be a trial of battle!" the class was getting excited that they'd be going full tilt.

"And to go with your first battle, we have prepared everyone's battle gear to the requests you have sent in!" he said while the wall to the far side slid open revealing metal briefcases with numbers on them.

"Aw hell yeah!" the class shouted.

"Get changed everyone, and gather at ground Beta!" All Might announced. Izuku grabbed his costume opened it to reveal the suit he commissioned. Walking into the boy's locker room, he put it on one layer at a time. Looking at himself in the mirror, the outfit looked rather good on him. It was a lab coat in whites and greens with a black shirt under the jacket. The coat was made of a bullet-resistant cloth while the inner shirt was designed to resist cuts from knives. The belt had several loops for Izuku to put his Bio-Glow into, which he had stocked around five. The cylinders were metal with a thick glass down the side to show him if it was empty or filled. He had also put a knife on the back of his belt, in case he needed it. On the other side of the belt from his vials was a large pocket for his first aid kit and a sleeve for a mini notebook. Holding his head high, he stepped out to the training field.

"Damn dude!" Eijiro exclaimed at his classmate. "You look like a mad scientist, 'specially with the glowing needles. That the stuff your quirk makes?"

"Yeah." the gene splicer admitted. "If the substance isn't used to change DNA, then it starts repairing injuries in soft tissue and nerves. A good method of first aid if you know what you're doing. Your costume is also really cool!" everyone else was waiting and talking until All Might coughed into his hand.

"Alright! You all look like real heroes now!" the large blonde said. "Now, for this exercise, we will be doing an indoor battle trial! Can anyone guess why?" Momo raised her hand and was called.

"It's because a majority of all villain activities are done out of sight and in confined spaces. With heroes patrolling the streets, it just makes sense to stay under the radar and inside buildings." All Might nodded.

"That's exactly right! Now, we will divide the class into teams of two and have two teams in each exercise; one team will play the villains while the other will be the heroes trying to stop them." All Might was then bombarded with different questions from everyone at the same time. "Hold up now! Let me finish, and see if that answers your questions! If they don't, _then_ you can speak up."

Everyone then heard the rules. The villains would protect a prop bomb for fifteen minutes, and the heroes would try to touch it. If they completed their goals or tied both of the opposing team, they won. When All Might told them about the random lots, Tenya spoke up.

"Sir! Wouldn't it be more advantageous to pick our partner?" the armored teen asked.

"Well yeah, but when are heroes able to choose who arrives at an incident with them?" Izuku pointed out, and the engine quirk-user conceded the point. Pulling lots, everyone found their partner and waited to see who would be facing who.

* * *

"The best plan is to bar up and preventing them from getting in." Momo said, pulling loose rubble and stacking it against the door.

"Do you honestly think that'd hold Kirishima for long?" Izuku countered. "Barricades are good, but we need to stall in other matters. Can you make a tape and recorder?"

"Yes?" there was obvious confusion in her voice. "How would that help?"

"I liked making horror stories with my uncle, and I thought voicing a certain conversation would give them pause. After that, you'd lay traps while I keep the heroes chasing shadows." there was a moment's pause as the nominated student took his plan into consideration.

"Alright, what script did you have in mind?" she liked a good horror as well, and thought with the building's poor lighting, it would have the desired effect. The gene splicer then pulled out his phone and went to the conversation he had in mind. Momo read through it and shivered.

"You want me to be the second voice?" she asked. The smile on the greenette's face made him look more like a mad scientist.

"Would you kindly?"

* * *

Eijiro and Ibara were finally allowed inside, and they walked through the front door. The vine-haired teen saw something glint from the sunlight, and went to check it out.

"Kirishima-san, I think our opponents left us something." she said, holding up an old-style tape recorder. Kirishima glanced at it curiously. Hitting the play button, they heard the conversation.

"Do you realize just how much this can tell us?" It was Izuku's voice, but the tone he held was emotionless, like he was watching a mold experiment.

"I just see the lives it'll take, but what did you have in mind?" Momo said, as if she was in mild awe of the "bomb". There was a tsk from the scientist.

"Bombs that utilize radioactive material as fuel leave large amounts of ionizing radiation that can take decades to leave." The brawler was starting to get nervous at the was the two were talking without inflection. "Tell me, what does that radiation do to the human genome, and what is the response?"

"It takes away parts of the genetic structure, and the body tries to fill in those gaps with the other half of an RNA sequence, but it often leads to mutations." the assistant said in a calm voice.

"Precisely dear, and while we may be charged for crimes against humanity, the target city was a base for a genetic research study, with almost a third of the city volunteering because of the compensation reward." there was a hum of approval from the other side of the conversation.

"Thus leaving more regulated individuals to have a natural case study from hundreds, if not _thousands_. We could accelerate research in this study while keeping a vast majority of the research teams in the clear from legal repercussions. But why this method?" she asked in curiosity. Ibara was starting to be concerned, already drawn into the story.

"Because I have no options left." the sadness in the voice spoke of loss. "My research confiscated, my home destroyed, my family dead, and now I'm wanted as nothing more than a petty thief for trying to reclaim what was mine." the spite in the scientist's voice was palpable.

"They saw me as a danger due to the nature of my research, well now the law will know me a far bigger danger with nothing to lose, and they will see that I can be a _far_ larger threat than _mere pieces of paper_!" the pure venom in the words made the threat that much more intimidating, and momo's response was almost dead in comparison.

"And I get to see death in a far more grand way than killing a shopkeep downtown." though not laced with the emotions of her partner, the cheery way she said it was _wrong_. "Here's to genocide!" she chirped, and the audio cut, leaving the room in dead silence.

"O-okay… this is starting to get really freaking morbid; they thought the best way to stall us was through _this_?" the hardening teen asked, voice shaking. His partner was taking deep breaths.

"Let us just proceed. This is merely a distraction." Ibara commented, though she was just as spooked. The heroes continued walking through the halls, going up floor after floor in a sweep.

There was nothing. No traps, no more creepy tapes, no villains in sight. Just utter silence as the two heroes were searching around; the only sounds were coming from their breaths and footfalls. As they came to the fourth floor, Izuku snuck up behind and grabbed the redhead, making sure he couldn't shout before running off.

" _Kirishima has been captured!_ " All Might called from the speaker system, making the vine-haired teen turn quickly. Now fully scared instead of unnerved, Ibara sent her vines out in a wide area around her before running up another set of stairs. Seeing a barricade, she shoved her way through with her quirk, leaving her in the room with the bomb, and Momo with a web of capture tape.

* * *

"Damn, Midoriya is scary. He took Kirishima without Shiozaki realizing until it was announced. Why didn't he try for her though?" Denki asked from the video room. The rest of the class had been watching, and while they didn't get audio, they saw Eijiro and Ibara tense at the message the villain team left.

"Most likely it was a calculated decision." Tenya spoke up. "As we saw Shiozaki-san use her quirk to cover her blindspot, we can assume Midoriya knew he would only be able to take one before the other hero would brace and make capture much harder. In a straight-up fight, Kirishima's Hardening would be difficult to plan around with anything other than brute force; Shiozaki-san's quirk, while more versatile, is easier to deal with when the proper tools are used. There's also the fact that trying to capture her would be harder in the first place as she could bind her attacker before they succeeded." there was a moment of silence as everyone took the information in. It dawned on most that Midoriya wasn't just strong; he was a strategist.

"I'm glad Midoriya is training to be a hero." Mezo chimed up. "I don't think I'd ever want to fight him for real."

"No kidding…" Mina whispered. As they talked, everyone kept their eyes on the screen.

* * *

Momo was having some trouble. She had wanted to burn the vine user's hair, but the plants were filled with liquid, making that rather hard. She was now using knives, but the vines were tougher than she thought. Thankfully, the bomb was on the far side of the room behind the capture tape she made, but sooner or later, the creation user was going to lose.

"Need a hand?" Izuku called from the ceiling, and Momo was more than happy to accept. Dropping down from above, the lanky teen's left hand was encased in ice, shards stabbing out from his fist. Thinking he was giving himself something to cut her vines, the hero backed up.

Unfortunately, that wasn't what he was doing.

With a flick of Izuku's wrist, the vines closest to the villain team gained a layer of frost, preventing them from bending as Momo smashed them with a metal rod. Ibara quickly tried to switch strategies, but the fewer vines made it harder. The vine user then decided that she needed to take Izuku down, as he was giving her more trouble. With the remaining tendrils she had, Ibara bound the tall teen, keeping him from using his ice.

And she received a bar of something dense to the chest courtesy of the opponent she lost sight of. Her vines went limp as Ibara struggled to find breath. She felt her wrists being tied and the signal going off, signaling the villains' win.

"You need me to take you the nurse?" Izuku asked with concern, kneeling down to her. She looked at the vials on his belt, but he shook his head. "Would you rather a kiss on the forehead, or a large needle being stabbed into you?"

"Nurse…" the vine-haired girl groaned and was quickly but smoothly rushed away in a princess carry. She found it funny given the green and violet victorian dress she had as her hero costume.

* * *

That's it for this chapter, but another one will come. I got the idea for Izuku's hero costume from (ironically) some artwork for a mad scientist villain Deku. As for the vials, the Bioshock 1 trailer when the guy stabbed himself to get Insect Swarm (though that particular plasmid will not be in Izuku's skillset.), and the syringe Elizabeth uses to revive Booker in Infinite; they look more durable than the glass cylinders in modern hospitals. If you liked my story so far, please leave a comment. Till next time!


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